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Monday, November 25, 2013

With the recent industry press indicating that T-Mobile was positioning its self to purchase Verizon's 700 MHz A Block, I decided to dive into the Spectrum Analysis Tool to see what kind of geographic area Verizon's licenses would provide T-Mobile with low band spectrum.

Clearly it would not be a spectrum purchase to provide coverage in rural areas since it doesn't address the rural areas in the western United States with the exception of western Colorado. Looking at it on a Cellular Market (CMA) basis, this spectrum would provide T-Mobile with low band spectrum in all 15 of the Top 20 markets but only 25 of the Top 50 markets. This includes both the Verizon spectrum and T-Mobile's 700MHz spectrum acquired from MetroPCS.

To acquire the remaining 700 MHz A block spectrum in the Top 20 markets, T-Mobile will need to be talking to:

Tuesday, November 19, 2013

As I was completing my research for an upcoming blog on LTE Carrier Aggregation, I found that my previous LTE Band Class reference sheet was missing some of the more recent Band Class updates, so I decided to share my new reference document with a few comments.

FDD Band Classes:

The first notable band class addition in Band 30. This band class creates a definition for FDD operation in the WCS (2.3GHz) band which was previously defined only for TDD operation.

From the Spectrum Grid view of the Spectrum Ownership and Analysis Tool, you can see that Band 30 does not include the 5MHz channels that AT&T purchased to essentially become guard bands for the Satellite Audio guys. This will provide AT&T with a 10x10 LTE channel on a market by market basis, as they resolve the remaining ownership issues in the WCS band.

The next two band classes are not new, but I previously skipped over these band classes because I didn't fully understand their frequency breaks.

Band 26
Previously I thought this was a specific band for Sprint IDEN operation that is adjacent to the cellular band. This is the band where Sprint is placing their 2nd LTE channel (5 MHz) and a CDMA channel (1.23 MHz). Looking at the frequencies in detail, the band class covers the IDEN spectrum and the adjacent cellular spectrum.

This is similar to Sprint's Band 25 which includes all of the PCS band plus their G block spectrum (but not the H block).

So you would think that all of the North American carriers could standardize to Band 25 for PCS operation and Band 26 for Cellular. Using the latest iPhone 5s LTE band support,

you can see the Verizon, T-Mobile, and AT&T iPhone's support Band 2 and 25 for PCS, but only the cellular band (Band 5). Sprint iPhone 5s includes,

both Band 2 and 25 for PCS and Band 5 and 26 for cellular.

Band 10:

This is referenced as the AWS extended band and you can note from above that it is not currently applied to smartphones like the iPhone 5s. This band class seems to be a preparation for the future use of the AWS-2 and AWS-3 spectrum and the government shared use band that are both adjacent to the existing AWS spectrum band. Here is how the downlink looks in the Spectrum Ownership Analysis Tool:

Note that Band 10 does not cover the entire band contemplated for AWS-3, nor does it include Dish's Band 23. For the uplink:

This again depicts that Band 10 is not currently set to include the entire shared government opportunity.

TDD Band Classes:

Here is the reference sheet the TDD band classes.

On this reference sheet I hadn't looked closely at band classes 35, 36, and 37. I had always focused on the 2.3GHz and 2.5GHz as the only bands that were designated for TDD support in North America. These three band classes create 140MHz block of spectrum that could be for TDD deployment. Here is how these bands appear in the Spectrum Ownership Analysis Tool:

I'm not sure what the history is on these band classes, but they would support TDD operation in both the PCS uplink and downlink bands as well as in the 20 MHz between the bands. Since the PCS frequencies are highly deployed, I would consider it very unlikely to see TDD systems in this band in the near future, and I doubt that the PCS band is authorized for TDD operation. It will be interesting to see whether any of the wireless carriers begin to look this direction. With Sprint stepping out of the H block auction, they seem to be signalling that TDD operation is more important to them and the Band 37 block (including Sprint's G block) could be the reason why Dish is pushing forward in the H block auction. Please comment if you are aware why the 3GPP has included these 3 TDD band classes.

Wednesday, November 13, 2013

Although it surprised the wireless industry a bit, it does make sense that Sprint saw a declining value in the H block spectrum. Acquiring that spectrum would have allowed Sprint to expand their primary LTE Channel from a 5x5 channel to a 10x10 channel. In terms of Mbps, from 37 Mbps per sector to 73 Mbps per sector. If this could be added to the network today, it would bring Sprint to about par with the other 3 national carriers. The problem is timing. It will be mid-2014 before the spectrum will be awarded to the auction winner, but prior to receiving the spectrum, the high bidder could start the 18-24 month process to get the LTE band classifications changed. Sprint would either have expanded the frequencies for their band 25 or requested a new band classification that would include all of the old PCS block, the PCS G block, and the PCS H block. With the standards body work, including carrier aggregation, it would likely by early 2016 before network upgrades would begin. This coincides with their forecasted completion of Project Spark. If Sprint completes this project on-time, they will have 38,000 sites that will be enabled with 40MHz of 2.5GHz spectrum, which could be a game changer. This does seem to signal that Sprint doesn't think their PCS G LTE is particularly strategic.

Wednesday, November 6, 2013

It is interesting to look at the details of Verizon's spectrum purchase from US Cellular in the St Louis market area (EA-96). Many industry sources talk about how purchase will provide 20MHz for Verizon's LTE. While this is true, it should not be confused with Verizon deploying a 20 x 20 channel. As can be seen from the Spectrum Grid view of AllNet Labs' Spectrum Ownership Analysis Tool, Verizon is purchasing the AWS B channel and previously owned the F channel. Although Verizon will own 20 MHz of spectrum, it is not contiguous and until they can deploy Release 12 software code into their network, they will have to operate this spectrum as two separate 10 MHz channels. Release 12 is likely a 2015 or maybe 2016 release since operators are either planning or deploying Release 10 currently.

The industry talks alot about Carrier Aggregation (CA) but there are several facts that are not well understood. First, Release 10 includes the functionality for carrier aggregation but the frequency band definitions for the US are not included until Release 11. Another point that needs to be understood is that the initial definitions require that aggregated carriers be in contiguous blocks in different spectrum bands (inter-band) or in separate blocks but in the same band (intra-band). For Release 11, only 2 carriers can be aggregated together. For Release 12, Verizon has sponsored a work group that will allow 3 carriers to be aggregated, 1 from the 700MHz band and 2 different carriers from the AWS band. Thus, Release 12 will be necessary for Verizon to aggregate their two AWS blocks of spectrum with their 700 MHz LTE.

The Spectrum Grid view is sorted by the EA geographical area which show that the AWS B and C licenses have not be dis-aggregated. The A channel licenses do show discontinuity since they were originally auctioned as CMA licenses. AT&T through their Leap purchase will strengthen their AWS ownership in this market.

To look at the competitive picture for spectrum in the St Louis market (EA-96) we can look at the

Company By Band worksheet from the AllNet Labs' Spectrum Ownership Analysis Tool. Looking first at Verizon, we can see the variety of spectrum depths across the EA that Verizon indicated in their FCC filing. Verizon will range from 62 MHz to 117 MHz depending on the county. The only county that Verizon controls 117 MHz is Montgomery County, MO which is 40 miles west of St. Louis.

Looking at the other carriers in this market we see that US Cellular will still control between 32 MHz and 69 MHz, while AT&T with their Leap purchase will control between 61 MHz and 105 MHz.

T-Mobile controls between 40 MHz and 60 MHz with two counties at 70 MHz and Sprint with their Clearwire purchase controls between 130 MHz and 242 MHz.

Friday, October 18, 2013

For the past month I have been examining the effect of WiFi off-loading based upon my usage habits. To do this leave WiFi turned off so my phone only receives data service from a commercial carrier network. This was not a simple task because the Smartphone network optimizer will continue to request to have WiFi turned on and whenever you are using location services (Google+) not having WiFi provides a notification "to improve you location, please turn on WiFi".

My typical monthly data usage averages around 1.3 GB per month with WiFi enabled. I travel infrequently and have WiFi both at home and work. I think it is important to note that my work WiFi doesn't block YouTube, Pandora, Facebook, or WatchESPN, but I typically use a WiFi only tablet for music streaming or the watching a major sporting event e.g The America's Cup or the MBL playoffs.

In the month of September, I ran 5.7 GB of data in what I consider to be a typical work month. What this equates to is 3.4 GB of data that was off-loaded from the carrier network to the WiFi network for which I also pay. Another way to look at it is that my carrier only sees 1/3 of my usage.

Using some of the wholesale data rates that have been thrown around in the trade press, $5/GB; the cost to support my data usage through a WiFi Off-loading provider would be $17/month. If I am paying my carrier $30/month for my data usage and they pay a Wi-Fi off-loading provider $17/month, they only end up with $13/month to offset their operational expenses (site leases, backhaul costs, employees...)

When you consider the "true" smartphone usage and where the majority of that traffic is handled today, it is clear why cellular carriers have been reluctant to purchase wholesale access to data or a WiFi off-loading partner.

Check back next month. After my billing period closed, I spent the weekend out of town, so streaming two college football games on Saturday (Dish Anywhere) and 1 NFL game on Sunday will all be part of my October usage. With just 9 days on my billing cycle, I have already consumed 3.3 GB.

Wednesday, October 16, 2013

With the news that Verizon is beginning to turn up some of their AWS spectrum with LTE, I will examine the spectrum available for those LTE deployments in the Top 5 CMAs with the Spectrum Ownership Analysis Tool.

New York:

Verizon clearly holds 20 MHz of AWS spectrum. To see how this spectrum will affect their total LTE capacity I have evaluated the LTE channels that Verizon can deploy based on their stated direction. Based upon Verizon's stated direction I have eliminated any 700 MHz 5x5 LTE channels, any cellular LTE channels, and any PCS LTE channels.

With this analysis, it is evident that Verizon will top out at 223 Mbps across all of the counties in the New York CMA.

Los Angeles:

In Los Angeles, I would expect Verizon to be deploying a 10 MHz LTE channel until AT&T has shifted its LTE usage of this AWS channel to it "new" 700MHz B band holding.

At this point Verizon is limited to 2 - 10x10 channels or 146 Mbps throughout the Los Angeles CMA.

In Philadelphia, the largest channel Verizon can form is a 10x10 channel. When AT&T gets control of the Leap spectrum assets, I would expect a three-way spectrum trade to allow Verizon, T-Mobile, and AT&T to rationalize their AWS spectrum positions.

For the throughput analysis, the additional 5x5 channel that Verizon can form in the AWS frequency band is included with the 2 - 10x10 channels (AWS and 700) for a total metro throughput of 183 Mbps.

Detroit:

In Detroit, Verizon can again form a 20x20 AWS channel.

In the Detroit CMA, Verizon can achieve a metro through put of 223 Mbps.

Tuesday, July 30, 2013

Sprint completed the 2Q - 2013 earning call this morning providing a few details about their plans for Clearwire's 2.5 GHz spectrum.

Sprint intends to overlay all of the 38,000 cell sites with the 2.5 GHz spectrum. Clearwire has stated previously that 40% of their 16,000 sites are at the same towers as Sprint. Steve Elfman clearly stated that the 2.5 GHz network would have a higher cell density, guaranteeing that 2.5GHz only sites will be prevalent in Sprint's network. Sprint has clearly signaled a return to the original Clearwire vision of a seamless, high capacity, high speed, wireless network.

Let's go through the site numbers:

1) Sprint expects 2000 sites supporting 2.5 GHz TDD-LTE this year. This was Clearwire's original commitment with the capacity hotspot mission. Clearwire had fairly firm plans to expand this site count to 5000 sites (hotspots).

2) 40% of Clearwire site (6,400) are located at the same tower as Sprint. Will Sprint move these sites onto their tower lease and back-haul? Saving the additional tower lease makes sense, but shifting the back-haul capacity from the "free" microwave back-haul, to Sprint's lease circuits would be adding a large and growing expense to Sprint's bottom line. A mis-understood fact on the wireless carrier back-haul is that although they will describe the back-haul as fiber back-haul with "unlimited bandwidth", the carriers are typically paying for bandwidth services delivered on fiber. This means, a 100 Mbps back-haul circuit is provided to the site on fiber for a cost based upon the back-haul capacity (100 Mbps). If Sprint added Clearwire's traffic to there existing back-haul, they would have to double or triple the capacity, probably doubling their overall back-haul expense.

Steve Elfman also made some interesting comments related to Sprint's 800 MHz spectrum (iDEN). He felt it was important to deploy for in-building penetration. I am still waiting to hear if there is a significant deployment of Sprint's 800 MHz spectrum in rural areas (with CDMA and LTE). If you look at the Virgin Mobile coverage maps, you can see the landmass covered by Sprint's network.

Expanses (non-green areas) in the West/Northwest and Southeast could utilize a Sprint 800 MHz greenfield build. I continue to believe that the primary benefit of lower band spectrum (600,700, Cellular) is coverage in less dense areas. I don't believe that there is a significant different building penetration improvement at the lower frequencies.

Friday, June 28, 2013

Verizon announced yesterday that they will be making their PCS spectrum available for LTE in 2015. If you are looking at a planning horizon, you could call this LTE Channel #3 for Verizon. Channel #1 is the 700MHz C Block Channel, Channel #2 is their AWS spectrum holding, and Channel #3 is now their PCS spectrum asset. Previously Verizon had indicated interest in Clearwire EBS/BRS spectrum which was their Channel #3 at that time, which has passed.

So what does this mean to Verizon and its customers? First, there are a limited number of markets where Verizon lacks cellular spectrum, so the PCS spectrum carries their voice traffic. See the Tulsa, OK, Spectrum Grid below:

In Tulsa, USCellular owns the B-band Cellular spectrum, highlighting a potential acquisition opportunity. Verizon holds 5MHz of spectrum in the PCS block for their voice services, along with 10MHz of AWS spectrum.

Looking at the contiguous spectrum that Verizon holds in each of the cellular market areas we see that the only market where they can create a 20x20 LTE channel with their PCS spectrum holding is in New York, NY. For the New York market, Verizon's PCS spectrum holding would permit 4 - 5x5 LTE Channels, or 2 - 10x10 LTE Channels, or 1 20x20 LTE Channel. Below are the results for Verizon's PCS Spectrum in Cellular markets 1-25. The fractional LTE channels (e.g. 2.1 - 5x5 LTE in Minneapolis) are caused by summarizing the number LTE channels in each market by averaging the LTE channel count for each county in that cellular market area (CMA).

Below are the results for Verizon's PCS Spectrum in Cellular markets 25-50. Clearly, deployment of Verizon's PCS spectrum with LTE will not provide as much additional capacity as their Channel #1 and Channel #2 plans, thus Verizon is still spectrum shopping for their 2015 LTE capacity.

T-Mobile announced an acquisition this morning of USCellular's AWS spectrum in several markets. This was clearly foreshadowed when I analyzed the Sprint - USCellular PCS spectrum deal earlier this year.

On this chart from the Spectrum Ownership Analysis Tool, you can see the PCS spectrum in Chicago and St. Louis that Sprint acquired along with the subscribers and network. Thus it was clear to see that USCellular's AWS(B) and AWS(E) spectrum was no longer needed.

It clearly makes sense for T-Mobile to acquire this spectrum as indicated in the chart below. In St Louis, T-Mobile will increase their LTE Channel size from 10MHz to 25MHz and in Kansas City, T-Mobile will increase from 10MHz to 15MHz. The chart also highlights the important spectrum position that Leap hold in the AWS band which both T-Mobile and Verizon would desire to add to their portfolio.

Thursday, June 27, 2013

With AT&T's announcement that they are meeting some challenges related to testing operation between LTE Band Class 29 and Band Classes 2 and 4, I figured that many readers would appreciate a reference map for how these band classes relate to the US mobile radio and satellite spectrum bands.

All of these screenshots are from the AllNet Labs Spectrum Ownership Analysis Tool, where we display and provide analysis tools related to spectrum ownership for all of the US mobile radio and satellite spectrum bands for all 50 states and US territories. AllNet Labs Spectrum Ownership Analysis Tool

In the images below, the band classes are color coded Gray for Uplink Spectrum, Yellow for Downlink Spectrum, and Blue for Spectrum supporting Time Division Duplex.

Wednesday, February 13, 2013

Recently I reviewed the 3GPP Standards site to check in on the status of LTE Carrier Aggregation. I found a gold mine of information.

First a few definitions: Carrier Aggregation allows a wireless carrier to band together different blocks of their spectrum to form a larger pipe for LTE. This can be accomplished in two ways: Inter-band and Intra-band.

Inter-band combines spectrum from two different bands. The spectrum in each band to be combined must be contiguous within that band. Intra-band combines spectrum from two non-contiguous areas of the same band.

Below is a table summarizing the relevant 3GPP working group descriptions for Carrier Aggregation.

First of all, the current network release for all carriers is Release 9. T-Mobile, Sprint, and Clearwire have announced that they are deploying Release 9 equipment that is software up-gradable to Release 10 (LTE Advance). From the chart, it does not appear that there are any carrier configurations planned until Release 11. Release 10 appears to be a late 2013 commercial appearance and Release 11 will likely be very late 2014 or mid-2015. For Carrier Aggregation to work it must be enabled and configured at the cell site base station and a compatible handset must be available. The handsets will transmit and receive their LTE data on two different spectrum bands for the Inter-band solution. All handsets currently only operate in one mode, 700MHz, Cellular, PCS, AWS, or 2.5GHz.

Highlights by Carrier:Canada: Rogers Wireless will have support for inter-band aggregation between their AWS spectrum and the paired blocks of 2.5GHz spectrum.

AT&T: Inter-band support in Release 11 for their Cellular and 700MHz spectrum, inter-band support to combine their AWS and Cellular spectrum, as well as configuration to support combining their PCS and 700MHz spectrum. All of the 700MHz band plans only include their 700B/C holdings. No 700MHz inter-operability.

USCellular: Inter-band support in Release 11 for Cellular and 700MHz (A/B/C). No support for PCS or AWS spectrum combinations

Clearwire: Intra-band support for the entire 2.5GHz band. China Mobile is also supporting this with an inter-band aggregation between 2.5GHz and their TDD 1.9GHz spectrum.

Sprint: Support in Release 12 for combining (intra-band)their holding across the PCS spectrum, including their G spectrum but not the un-auctioned H spectrum. No band support for their iDEN band or the 2.5GHz band.

T-Mobile: Support in Release 12 for intra-band in the AWS band and inter-band between AWS and PCS.

Verizon: Ericsson appears to be supporting Verizon's need to combine (inter-band) between AWS and 700MHz C. Not support for Verizon's Cellular or PCS holdings.

Dish: Release 12 support to combine their S band (AWS4) spectrum (inter-band) with the 700 MHz E holdings. This is the only aggregation scenerio for the US that combines FDD operation (AWS4) with TDD operation (700MHz E).

Tuesday, February 12, 2013

In listening to the wireless carrier earnings calls for 4Q2012, many of the analysts are interested in the timing for offering VoLTE. VoLTE stands for Voice over LTE, in other words, Carrier VoIP. It is unclear whether the carriers are looking at this as a launch of a handset supporting only VoLTE or whether it is essentially a dual-mode handset providing VoLTE where the quality is acceptable and traditional 2G or 3G voice everywhere else.

There is no doubt that 4G speeds enable VoLTE and all of the other VoIP over-the-top (OTT) providers like Skype, OOMA, and GoogleTalk. Carriers will have the ability to better control their customer experience with their VoLTE service since they can change the QOS settings because they can identify the data as a voice call.

I believe that Verizon has essentially stamped a date for their networks being 100% VoLTE for voice as the same 2021 data for shutting down CDMA. This is a reason time frame for networks to mature so they are capable of supporting VoIP seamlessly across the carriers footprint.

A key consideration that is not openly discussed, is the fact that the traditional wireless carriers that began as wireless voice providers have only overlaid their 4G data networks on top of a network that was originally designed for voice. This is important because capacity is impacted differently on a voice network than a data network. A voice user, whether 100ft or 4 miles from a site, essentially consumes the same amount of voice capacity. A data user, 100ft from the site, is capable of transmitting his data with a high efficient data modulation scheme, which reduces the capacity burden on the cell site. A user, 4 miles from the site, will receive his data using a more robust modulation scheme with a significant cost to the site's capacity. In this example the first user transmits his data on a train that has 64 cars for data, while the user 4 miles from the site only has 4 cars to carry his data.

How does this affect VoIP and the launch of VoLTE? With the diagram above I have indicated the areas of each cell site that will have high, medium, and low capacity based upon their voice network design. These are the areas that VoIP voice quality will suffer due to lack of coverage or capacity. With each carrier only offering LTE on one channel, the option to add additional spectrum to solve the capacity issue is not available. Carriers are pursuing small cell solutions to meet this capacity need but it will require extensive time to mature the networks to support VoLTE and VoIP on a standalone basis.

Thursday, January 24, 2013

There is a little buzz this morning about an application from Google to construct a experimental network on 2.5GHz frequencies on the Mountain View, CA campus. Here is a link to the application. The application states that they will be using spectrum between 2.524 and 2.546GHz and between 2.567 and 2.625GHz. The top issues with this application is that Clearwire operates their WiMax network within this market and has states on their earnings calls that they typically deploy using between 30MHz and 60MHz of spectrum. Google would need to guarantee that there would be no harmful effect to this commercial network. Now lets look at the specific spectrum allocations.

In the above image from my Spectrum Ownership Landscape Report, you can see that the lower band matches correctly to the B2, B3, C1, and C2 channels. The upper band matches the LTE Band 38 so there would appear to be a desire to test TDD-LTE equipment in that portion of the band.

Can Google do this without Clearwire's agreement and assistance? I don't think so. The B2,B3 channels are owned by The Santa Clara Board of Education (Call Sign WHG338) and don't appear to be leased to Clearwire so they are ok. C1,C2 (Call Sign WHR466) are owned by The Assocation for Continuing Education and they appear to be leased to Clearwire. The spectrum in Band 38 is particularly interesting. First of all, it is the portion of the spectrum that is currently dedicated to video operation, so Google would need to work with each of the broadcasters and convince them that their operation in Mountain View would not interfer with the ability of the broadcaster's clients to receive their desire video broadcast. In addition, the presence of this high powered video interference would make Google's tests much more challenging, especially outdoors. On the far right of the spectrum allocation Google has requested is the BRS2 channel that is clearly owned by Clearwire.

For the video spectrum, Clearwire still holds the leases for the A4, C4, D4, E4, and F4 channels. I anticipate that Clearwire is not supportive of this testing without their involvement and they will protest the experimental authorization. In my history with with wireless carriers, it was not unusual to see a experimental application for my carrier's spectrum without being contacted directly for the use of my carrier's spectrum.

Wednesday, January 23, 2013

Verizon's announced last week that they were looking into broadcasting multicast video utilizing the LTE Broadcast feature, known in the standard as EMBMS - Evolved Multimedia Broadcast / Multicast Service. After watching a video interview by Dan Meyer with RCR Wireless with Lynette Luna from Current Analysis I thought a short description of the challenge of multicast video would be in order.

The goal transmitting multicast video is to limit the number of unique video sessions that are coming into your network, loading your switches, routers, cell site backhaul, and finally cell site RF capacity. In the diagram above I have shown Netflix/You Tube video traffic in red. From Dan and Lynette's conversation, this would be considered Over the Top (OTT) video, essentially video not provided or managed by the network carrier. With 3 handsets all receiving a unique You Tube video or Netflix movie, there are 3 streams of video capacity (red circles) used at the market switch (2 are shown). The South Market Switch still is burdened with 3 video streams. The backhaul to the 1st cell site on the South market switch is still carrying all three video streams, but since no users are on the 1st cell site, no RF coverage is consumed. The link between the 1st and 2nd site still carries 3 video streams while the link between the 2nd and 3rd site only carries 2 video streams.

Looking at the North Market Switch we can see what is desired with multicasting video. The key is to realize that this video is synchronized for all users like a live sports game or a broadcast television program that starts at the same time for all users. The network will have the intelligence to recognize that multiple users are requesting the same video stream and it will only set it up once on each switch, cell site backhaul, and cell site that has a user requesting the service. You can see that there is one site off the North Market Switch that does not have a Live Broadcast User, thus neither the site or the site backhaul would be carrying that video stream, eliminating that required capacity.

I see this as a limited offloading opportunity. US Consumers have been trained with DVRs to timeshift TV viewing and to utilize Quickskipping to eliminate commercials. For consumers, applications like Dish Anywhere which allows me to record my programs, including Live Sports, and send them to my handset when I want to start them, will continue to be very popular. This would be an OTT video example that I gave above. Wireless carrier's could enable DVR functionality in the handset, allowing the customer to pause the live broadcast at their handset and continue playback at their convenience, but that is an expensive handset that doesn't exist today.

Tuesday, January 22, 2013

Globalstar's Proposed Terrestrial Low-Power Service (TLPS) has some well thought-out approaches. Globalstar has petitioned the FCC to allow them to utilize their 2484-2500 MHz "Big Leo" satellite spectrum to provide terrestrial coverage.

Globalstar's spectrum lies directly above the 2.4GHz ISM band which hosts a vast majority of the WiFi in use today, as well as bluetooth and microwave ovens. Directly above the Globalstar spectrum is the EBS/BRS spectrum controlled primarily by Clearwire.

Globalstar has proposed terrestrial operation on a the newly named AWS5 band. It would essentially be a 4th non-overlapping WiFi channel (Channels 1,6,and 11 are the primary non-overlapping WiFi channels). It would still be a 22MHz wide channel, using the ISM band above Channel 11 (which is lightly used) and about 10MHz of their AWS5 channel. Globalstar believes that most existing WiFi devices could support this spectrum with a over-the-air software updates so a massive number of devices could be overloaded to this network once it is constructed.

Also intriguing is the improved performance characteristics of this spectrum. First, since it is licensed to Globalstar, they can control the use of the spectrum. They envision a carrier grade network using this spectrum that would manage Hotspot power levels and interference. Since this spectrum has much less interference, it is capable of covering larger areas with higher speeds than typical WiFi.

If Globalstar can figure out the backhaul aspect to providing this service, I think they will have a leg up on other white-glove WiFi service providers since they are better able to manage the RF environment for their frequencies. It is conceivable that Globalstar would host WiFi overloading for all of the 4 national carriers. I still see the biggest challenge to be in a residential environment where they envision a hotspot in my house being under their control, but likely on my cable internet service. I'm pretty sure Comcast won't react well to my residential internet service supporting a commercial operation.

Is this a service that could be considered or expanded into the EBS/BRS channels that are adjacent to Globalstar's spectrum? The answer is yes. Clearwire has stated that they have excess spectrum. I would anticipate that this would look like a private LTE network on Clearwire's spectrum versus WiFi on Globalstar's, but it would not be as feasible as Globalstar's proposal due to the current lack of devices that support LTE on the EBS/BRS frequencies.

Wednesday, January 9, 2013

Dish's counter-offer for Clearwire is intriguing. I recently completed a presentation detailing the challenges of a spectrum sale in the EBS/BRS spectrum. Clearwire's press release states that this offer was on the table when Sprint's offer was received but Sprint's offer was deemed better. Tim Farrar's Blog indicates that the spectrum sale would likely be for Clearwire's BRS spectrum. This is a realistic assumption. In my presentation (linked in a previous blog) I highlighted that one of the primary problems with the leased spectrum is that it has limited geographic coverage, covering many of the dense metro areas but not contiguous all the way to a county or BTA border. There are still a few elements of a BRS spectrum sale that should be understood.

From the image above, the BRS spectrum sale would include the Orange (BRS1/BRS2) channels, the Pink (E channels), Light Blue (F channels) and Brown (H channels). This would equate to one contiguous block of 55.5MHz of spectrum, a 12MHz block of spectrum (E4,F4), and the isolated BRS1 channel. The 12MHz block could only be used if mid-band video operations have ceased in a market. Currently, I don't believe that any of the Top 10 markets have completed ceased video operations. The 55MHz of spectrum can support 2 - 20MHz TDD-LTE channels. This would virtually eliminate the ability to utilize the EBS/BRS spectrum for any FDD-LTE operations. It may be possible with a guardband in the H channels to operate the D channels and G channels in a FDD-LTE configuration.

In looking at the LTE Bandplans, the potential Dish spectrum allocation would miss the international TDD-LTE Band 38 which Softbank, China Mobile, and the UK auctions are using. We will have to watch carefully to see if international devices will include functionality of Band 41.

My last area of concern is whether that will leave enough spectrum for Clearwire to continue to operate their WiMax network as they bring their TDD-LTE network online. Additionally, with the geographic limitations of the leased channels, there may be a limited number of sites operating on Clearwire's network today, that won't have available spectrum without the owned channel spectrum.

Friday, January 4, 2013

Interesting facts from the Small Cell Rulemaking. A signal at 3.5GHz would have 29% reduced range compared to BRS/EBS (2.5GHz), 45% compared to PCS (1.9GHz) and 75% compared to the Cellular (850MHz) bands.

Half of this band is currently used for receive frequencies for earth/satellite stations in 37 cites and adjacent radar systems exist from 3650-3700MHz.

There will be large exclusion zones due to incumbent use of the spectrum. West Coast, East Coast, Gulf Coast, Hawaii, and Guam. Approximately 190 million people or 60% of the US population would not have access to small cell technology in the 3.5GHz band. From the map below, the only Top 10 markets that could use this frequency band would be Chicago and Detroit with Detroit being a question mark due to issues with Canada.

FCC 12-148A1 - Figure 2

FCC Small Cell Definition

Small cells are low-powered wireless base stations intended to cover small indoor or outdoor areas ranging in size from homes and offices to stadiums, shopping malls, and metropolitan outdoor spaces. Small cells are typically used to extend wireless coverage to areas where macro cell signals are weak or to provide additional data capacity in areas where existing macro cells are overloaded. Small cells are also characterized by their inclusion of novel sensing technologies such as environmental recognition and auto-configuration. (Paragraph 30, FCC 12-148A1)

General Authorized Access (GAA) - commercial, opportunistic users as well as business and homeowners. GAA users would be required to register in the SAS.

A Spectrum Access System (SAS) similar to the Television Whitespace Database used to coordinate unlicensed usage of the UHF broadcast TV whitespace. SAS would manage CBS access and ensure that lower tiered users will not harm federal and FSS users.